Transmission



P. ORR 2,375,816

TRANSMISS ION Filed March 25, 194 2 2 Sheets-Sheet 1 ,QQI/ 5m 2129 q 76 d3 i egi 70 Governor 67 77 219 ay' 15, 1945. ORR 2,375,816

TRANSMI SS ION Filed March 25, 1942 2 Sheets-Sheet 2 Palmer" 07"?" Patented May 15, 1945 TRANSMISSION Palmer Orr, Muncie, Ind., assignor to Borg- Warner Corporation tion of Illinois Chicago, 111., a corpora- Application March 25, 1942, Serial No. 436,083

12 Claims.

This invention relates to motor vehicle transmissions of the type in which the ignition of the vehicle engine is interrupted in order to relieve the torque load on interengaging drive control elements which, when engaged, are adapted to establish a drive of one ratio and when disengaged, to permit a drive of a diiierent ratio to be established through the transmission. In transmissions of this type, it is customary to employ a manual switch, preferably operated by the engine throttle, for forcing down the drive from one ratio to another, the interrupting of the ignition circuit being effected simultaneously with the energization of an electromagnetic device for controlling the engagement and disengagement of the drive control elements. Such electromag netic device is customarily in the form of a solenoid incorporating an ignition restoring switch made operative by the disengagement of the drive control elements. It is customary to employ relays in the ignition circuit and in "the solenoid energizing circuit. In the present practice, interruption of the ignition is effected by shortcircuiting the same. This may be designated a closed circuit system.

One of the characteristics of such a closed circuit system is that there is a drain on the battery during each ignition interruption, which is heavier than the normal load imposed by the ignition mechanism. This not only creates a burden upon the battery but also deteriorates the circuit breakers of the ignition system.

The primary object of the present invention is to provide an open circuit system, in which the ignition circuit is interrupted by opening the same instead of by shorting the same, and to provide such a circuit with a minimum of change in the control system now in use in overdrive transmissions. Particularly it is aimed to employ the same solenoid construction including the ignition restoring switch.

In general, this is accomplished by providing an arrangement in which there are two throttleoperated switches arrangedv to be opened in unison by the depression of the throttle control member, one of these switches being adapted to effect deenergization of the solenoid and the other being adapted to open one of two parallel ignition circuits the other of which is open at all times when the drive control elements are engaged and is adapted to be closed upon disengagement of the drive control elements, so as to restore the ignition. The control of this latter ignition circuit is effected by a relay incorporating a self-closing switch which forms part of the ignition circuit, this switch being opened by energization of the relay, which in turn is efiected by the closing of the switch in the solenoid when the drive control elements are engaged.

A more general object of the invention is to provide a transmission control circuit in which automatic means is provided for establishing a drive of one ratio and in which there is provided manual means for shifting the drive from that ratio back to another ratio, in the form of a pair of switches adapted to be opened in unison, the opening of one switch serving to react upon a solenoid which controls the interengaging drive control elements and the opening of the other switch serving to open one of two parallel ignition circuits the other of whichis standing open at the time, thereby to relieve the torque load on the drive control elements and permit them to be disengaged.

Other objects the advantages and uses of the invention will become more apparent after reading the following specification and claims, and after consideration of the drawings forming a part of the specification, wherein:

Fig. 1 is a schematic view of the control mechanism of an overdrive transmission embodying the invention, the parts being shown in direct drive position;

Fig. 2 is a similar view with the parts shown in overdrive position;

Fig. 3 is a schematic view of an overdrive control mechanism embodying a modified form of the invention; and

Fig. 4 is a schematic line drawing of a transmission to which this invention may be applied.

As an example of one form in which the invention may be embodied, I have shown in Figs. 1 and 2 the control mechanism of an overdrive transmission in which the mechanical parts, i. e. the planetary gearing, clutches, sun gear braking mechanism, and governor are constructed and arranged as shown in Fig. l of the pending application of Harold E. Carnagua, Serial No. 309,718, filed December 18, 1939.

Such an overdrive transmission (Fig. 4), which is well known and extensively used, includes planetary gearing it which is adapted, when the sun gear Hi thereof is braked, to transmit an overdrive from the input shaft It to the output shaft l9, and an overrunnin clutch 24 which is adapted to pick up the drive in direct ratio when the drive through the planetary gearing I2 is released by releasing the sun gear for rotation.

The sun gear braking mechanism includes a slotted locking ring which is attached to the sun gear. This slotted ring is shown in the drawings of the present invention at 22 and cooperates with apawl 4l which is adapted to engage in one of a number of slots 43 in the periphery thereof so as to lock the sun gear against rotation. A

solenoid, indicated generally at 8|, is adapted, when energized, to urge the pawl 41 toward engagement with the annular member 42. Such engagement is prevented, as long as the sun gear is rotating, by a balk ring 58 which has a slipping clutch connection with the sun gear and thus tends to rotate with the locking ring 42. When the pawl 41 is thus biased toward engagement, the engagement may be completed by throttling down the engine, thus placing a coast load on the planetary gearing and causing the sun gear, which has previously been rotating, along with the rest of the planetary gearing", in unison with the driven shaft, to slow down and finally to commence rotating in reverse. rotation will carry the balk ring 58 to a position wherein the pawl 41 may pass through an opening 53in the balk ring, into one of the slots 43 of the locking ring.

The pawl 47 is connected to the armature II of the solenoid 8| by means of a rod 65 which is slidably received in a longitudinal bore in the.

armature and receives pawl projecting thrust from the armature, through the medium of a coil spring 83 engaged between a flange I8 on the rod 65 and a cap 15 on the end of the armature. When the solenoid is energized, the armature II is drawn toward the pawl 41, compressing the spring 83, which, when the balk ring 58 permits the pawl 41 to advance, pushes the pawl 41 into one of the slots 43. r

The solenoid 8| includes a moving coil 88 and a holding coil 8| both of which are energized for biasing the pawl toward braking position, the coil 88 being deenergized when the pawl 41 goes into the slot 43 and the coil 8| remaining energized for holding the pawl in the slot. The deenergization of the coil 88 is accomplished by a switch including contacts 85 and 88, the latter being carried by an arm 81 which is disposed so as to be engaged by a flange IE on the cap I5, as the armature advances.

When the circuit through the holding coil 8| is broken, the armature is retracted by a spring 11 engagedbetween the flange I6 and an abutment I8 in the solenoid casing. The solenoid includes a self-closing switch embodying a pair of contacts I35 and I36 the former being carried by a switch arm I 31 whichis biased toward the closing position as indicated by the schematic representation of a spring I38.

The purpose of the switch I35, I38 is to restore the ignition of the motor vehicle in which the overdrive transmission is embodied, after the ignition has been momentarily interrupted for the purpose of relieving the torque load on the locking ring 42 and thus permitting the pawl 41 to be withdrawn by the spring 11.

The foregoing structure all forms part of the conventional overdrive transmission disclosed in the pending application Serial No. 309,718 referred to above. Such a conventional overdrive transmission also includes the motor ignition I42, the conventional battery 9| which energizes the solenoid 8| as well as the ignition I42, the ignition switch I43, and a rail switch III! which functions to open the solenoid circuit when the conventional manually shifted transmission of the motor vehicle is shifted to reverse drive. In the conventional arrangement, the switch I35, I36 is inthe shunt circuit by means of which the ignition is shorted out.

The conventional control arrangement also in- This reversal of cludes a manual control device for opening the solenoid circuit when the governor 98 is in circuit closing position, thereby to permit the transmission to be forced back into direct drive when operating in the overdrive range of speeds. This manual control customarily includes a switch in series with the governor 98, such switch including switch contacts I84 bridged by a connector I85 mounted on a push rod I88 which is adapted to be operated by the accelerator pedal. It is also customary to employ a relay of some kind, such as the relay ||3 including an energizing coil I88 and a pair of contacts I89 and N8, the latter being-carried by a switch arm I I I biased as indicated at I I2 to open position of the contacts and adapted to be drawn to closed position when the coil I88 is energized.

As previously stated, the primary purpose of the present invention is to utilize the above described parts with as little change as possible in an overdrive control arrangement in which the ignition is interrupted by opening the ignition circuit rather than by shorting it. To this end, I provide two parallel ignition circuits, one of which is open when the sun gear locking pawl is engaged, and the other of which is adapted to be opened in unison with the opening of the manually operated switch which opens the solenoid circuit, thus temporarily leaving both circuits open. The first mentioned ignition circuit is then closed by the retraction of the braking pawl. For convenience in referring to them, these circuits may be designated as the first and second circuits, respectively.

The first circuit includes, in series in the order named, the battery 9|, a conductor 288, the ignition switch I43, a conductor 28| contacts 282 and 283 of a relay 284, a conductor 285, and the ignition I42. The arm 286 on which the contact 282 is carried is spring biased toward closed position as indicated at 281, and is adapted to be moved to open position by the energizing coil 288 of the relay 284.

The relay coil 288 is in the control circuit of the relay, which includes, in series in the order named, the battery 9|, the conductor 288, the ignition switch I43, the conductor 28I, the coil 288, a conductor 289, and the switch contacts I35 and I36, the latter being grounded as at 2").

The second ignition circuit includes, in series in the order named, the battery 9|, conductor 288, switch I43, a conductor 2| I, a manual switch comprising the contacts 2| 2 and 2| 3 bridged by a connector 2| [mounted on the rod I86 of the manual control mechanism, a conductor 2| 5, and the ignition I42.

The solenoid energizing circuit includes, in series .in the order named, the battery 9|, 9. conductor 2I6, the relay contacts I88 and I I8, a conductor 2", the rail switch I81, a conductor 2|8 and the coils 88 and BI which are connected in parallel to the end of the conductor 2|8, the coil 88 being grounded at 2I8 through the switch 85, 85 and the coil 8| being directly grounded at 228.

The control circuit for the relay ||3 includes, in series in the order named, the battery 9|, the conductor 216, the relay energizing coil I88, a conductor 22I, the switch I 84, I85, a conductor 222, the governor 88, and a ground connection 223 for the latter.

In the prior conventional arrangements, it has been customary to employ a single relay having two sets of switch contacts. In the present invention, I employ two relays, each having a. single set of contacts, and a novel arrangement of manual switches in which two switches, on in the solenoid control circuit and the other in the secondary ignition circuit, are arranged to be opened and closed in unison.

In the operation of the mechanism, in direct drive relationship (Fig. l) the rail switch It! will be closed, the governor 38 will be open, and the manual switch ltd, will be closed. Accordingly, when the governor t8 closes as a result of raising the speed to the overdrive range, the solenoid control circuit will be completed, energizing the relay coil H18, closing the relay switch Hi9, H0, and thus energizin the solenoid circuit. The armature ll will thereupon be pulled forwardly by the coils 8t and iii, moving the pawl 41 into engagement with the balk ring 50 and thereafter compressing the spring 83. With these conditions established, the transmission will continue to operate in direct drive ratio until the operator relieves the pressure on the accelerator pedal, throttling down the engine, imposing a coast load on the planetary gearing and causing the sun gear which has been rotating in the direction indicated by the arrow 224, to slow down and finally commence to rotate in the opposite direction. This will cause the balk ring 50 which has been held against rotation by the engagement of its projection 225 with the pawl 41, to rotate away from the pawl, bringing the opening 53 thereof into register with the pawl and permitting the pawl to drop into the opening 53, and thence into the next slot 43 which registers with it. As the pawl 47 drops into the slot 43, the switch 85, 86 is kicked open by the flange E6 of the armature ll, thus deenergizing the moving coil 88 and leaving the holding coil 8i energized to maintain the pawl in engagement with the lockin ring. The gearing is now set for overdrive operation, which will continue until the circult through the holding coil 8| is broken.

While the pawl i"! has been held in disengaged position, the switch I35, H36 has been held open by the engagement of a stem I on the end of the pawl rod 85 against the arm l3'l, permitting the relay an to remainclosed. As the pawl 41 drops into the slot 43, the stem l26 will move away from the arm lat-l, permitting the switch I35, l38 to close. This energizes the relay coil 2%, causing the switch contacts 262, 203 to separate and thus opening the first ignition circuit.

The position of the parts in overdrive relationship is shown in Fig. 2. It will be noted that the circuit to the solenoid remains closed and the coil 8i remains energized to hold the pawl ll in engaged position. The relay 20 1 stands open, thus setting the circuit for kickdown operation, which may be effected by depressing the accelerator pedal to the full limit of its possible movement, either to or past the full throttle position. When the throttle is thus depressed, the switch I64, 15 will open, deenergizing the holding coil 8i so as to permit the spring II to bias the pawl a! to retracted position and the switch 2|2-2|Li will simultaneously open, opening the second ignition circuit, momentaril interrupting the lenition, relieving the torque load on the sun gear locking ring 42, permitting the pawl All to be withdrawn by the spring Ti, and thus rendering the planetary gearing inoperative and restoring the drive through the direct drive mechanism.

It may be noted that in the present invention, the arrangement does not provide for interrupting the ignition when the solenoid circuit is opened by the governor 88. In prior arrangements, this has been provided for, but I find that without them.

it is not necessary, since the opening of the solenoid circuit by the governor 98 will ordinarily be followed within a reasonably short time by a reversal of torque load arising from the natural manipulation of the accelerator pedal, and there is no necessity for immediate change from overdrive to direct drive relationship, under governor operation. I If an emergency requires an immediate change of this kind, the kickdown operation may be resorted to.

In some prior arrangements, use has been made of a delayed action relay for assuring the restoration of ignition under certain unusual conditions, as for example where the locking ring is in engagement with the pawl under a coast load by the time that the manual switch is operated to force the transmission from over-drive bacl; into direct drive. In the present invention, no delayed action relays are employed, and I find that the arrangement shown operates satisfactorily In the event that the solenoid should fail to retract the pawl during kickdown operation of the manual switch, the operator may simply release the switch and start the kickdown operation over again.

In the modified circuit shown in Fig. 3, theignition restoring switch l35a, 635a is included directly in the primary ignition circuit, the sec and relay being eliminated. In order to accomplish this, the switch a, l3fia is arranged to be self-opening, the switch arm I310. being spring biased toward open position as indicated at l38a. The switch is closed by the stern I25. The primary ignition circuit thus includes, in the order named, the battery 91, the ignition switch M3, a conductor 230, the switch 135a, l36a, a conductor 23l, and the ignition i l-2, The second ignition circuit and all other parts remain the same as shown in Figs. 1 and 2, and are given the salne reference characters.

The form of the invention shown in Fig. 1 is preferred because it avoids running ignition wires under the floor of the vehicle. It also has the advantage of avoiding any change in the conventional ignition restoring switch.

While I have described my invention in connection with one specific embodiment thereof, it is to be understood that this is by way of illustration and not by way of limitation and the scope of my invention is defined solely by the appended claims which should be construed as broadly as the prior art will permit.

I claim:

1. Control mechanism for a multiple drive ratio transmission of a motor vehicle including an engine having ignition means and including positively interengageable drive control elements adapted when disengaged to permit the transmission to operate in one drive ratio and when engaged to establish another drive ratio, said elements being subject to torque loads when engaged and being freely disengageable only when said loads are relieved; said control mechanism comprising electromagnetic means adapted when energized to urge one of said elements toward engagement with the 'other, yielding means to urge said one element toward disengaged position, means for establishing an energizing circuit through said electromagnetic means, means for establishing two circuits in parallel through said ignition means for energizing the same, said last means including a switch controlled in accordance with the position of said one drive control element, adapted to open one of said ignition circuits when said drive control elements are engages, and inducing a first manual Switch for opening the other of said ignition circuits so as to interrupt the ignition and relieve the torque load on said drive control elements, said means for establishing an energizing circuit through said electromagnetic means including a second manual switch arranged to be opened in unison with said first manual switch and to thereby effeet the deenergization of said electromagnetic means so as to permit said yielding means to move said one element to disengaged position.

2. Control mechanism as defined in claim 1, wherein said means for establishing an energizing circuit through the electromagnetic means further includs a speed responsive switch in series with said second manual switch.

3. Control mechanism as defined in claim 1, wherein said means 7 for establishing parallel ignition circuits includes a relay incorporating a self-closing switch which forms a part of the first described ignition circuit and a self-closing switch arranged to be opened as a result of disengagemerit of said drive control elements, for conwherein said means for establishing parallel ignition circuits includes a self-opening switch forming part of the first described ignition circult, said self-opening switch being arranged to be closed as a result of the disengagement of said drive control elements.

5. Control mechanism as defined in claim 1, wherein said means for establishing an energizing circuit through the electromagnetic means includes a relay incorporating, v a self-opening switch forming part of said energizing circuit and primary control means for controlling the energizat'ion of said relay, said primary control means including said second manual switch and a governor operated switch in series.

6. Control mechanism as defined in claim 1, wherein said means for establishing an energizin circuit through said electromagnetic means includes a self-opening relay switch and a reverse shift controlled switch in series in said energizing circuit and wherein said second manual switch forms part of a control circuit for efiecting the energiz'ation of said relay.

'7. Control mechanism for a multiple drive ratio power transmission of a motor vehicle having an engine including ignition means, relatively fast speed driving means including positively interengageable drive control elements adapted to establish a drive therethrough when engaged, said elements being subject to torque loads when en-' gaged and being freely disengageable only when said loads are relieved, and relatively slow speed driving means including a device automatically operable to establish a drive therethrough in response to release of the fast speed driving means; said control mechanism comprising electromagnetic means adapted when energized to urge one of said elements toward engagement with the other, yielding means to ulge said one element toward disengaged position, means for establishing an energizing circuit through said electromagnetic means, means for establishing two circuits in parallel through said ignition means for energizing the same, said last means including a switch controlled in accordance with the position of said drive control elements, adapted to open one of said ignition circuits when said drive control elements are engaged; and including a first manual switch for opening the other of said ignition circuits so as to interrupt the ignition and relieve the torque loads on said drive control elements, said means for establishing an energizing circuit through said electromagnetic means including a second manual switch arranged to be opened in unison with said first manual switch and to thereby effect the deenergization of said electromagnetic means so as to permit said yielding mean to move said one element to disengaged position.

8; Control mechanism for a multiple drive ratio power transmission of a motor vehicle including an engine having ignition means and throttle control means therefor, positively interengageable drive control element adapted when disengaged to permit the transmission to operate in one drive ratio and when engaged to establish another drive ratio, said elements being subject to torque loads when engaged and being freely disengageable only when said loads are relieved; said control mechanism comprising electromagnetic means adapted when energized to urge one of said elemerits toward engagement with the other, yielding means to urge said one element toward disengaged position, means for establishing an energiz'ing' circuit through said electromagnetic means, means for establishing two circuits in parallel through said ignition means for energizing the same, said last means including means responsii e'to movement of said drive control elements for opening one of said ignition circuits when said drive control elements are disengaged and including a throttle-operated switch for opening the second of said ignition circuits so as to interrupt the ignition and relieve the load on said drive control elements, and a second throttleoperated switch forming part of the means for establishing an energizing circuit through said electromagnetic means, adapted to be opened in unison with said first mentioned throttle operated switch and to thereby effect the deenergization of said electromagnetic means so as to permit said yielding means to disengage said eletransmission of a motor vehicle including an engine havin ignition means, a rotatable element adapted to be braked to establish one drive ratio, means including a device automatically operable to establish a drive of a different ratio upon release of said elements for rotation, and a braking pawl adapted to positively interengage with said rotatable element for braking the same; said control mechanism comprising electromagnetic means adapted when energized to urge said pawl toward braking position, means for establishing an energizing circuit through said electromagnetic means, means for establishing two circuits in parallel through said ignition means for energizing thesame', said last means including means responsive to disengagement of said pawl for opening one of said ignition circuits and including a manual switch for opening the other of said ignition circuits so as to interrupt the ignition and relieve the torque load on said rotatable element, and a second manual switch forming part of the means for establishing an energizing circuit through said electromagnetic mean arranged to be opened in unison with said first mentioned manual switch and, when thus opened, to effect the deeiiergization of said electromagnetic means.

lO Control mechanism for a multiple drive ratio'transmission ofa motor vehicle including an engine having ignition means, and including positively interengageable drive control elements adapted when disengaged to permit the transmission to operate in one drive ratio and when engaged to establish another drive ratio, said elements being subject to torque loads when engaged and being freely disengageable only when said loads are relieved; said control mechanism com prising electromagnetic means adapted when energized to urge one of said elements in one direction of its movement, yielding means to urge said one element in the opposite direction, means establishing an energizing circuit through said electromagnetic means, means for establishing two circuits in parallel through said ignition means for energizing the same, said last means including a switch controlled in accordance with a position of said one drive control element, adapted to effect the opening of one of said ignition circuits when said drive control elements are engaged, and including a first manual switch for effecting the opening of the other of said ignition circuits so as to interrupt the ignition and relieve the torque load on said drive control elements, said means for establishingan energizing circuit through said electromagnetic means including a second manual switch arranged to be actuated in unison with said first manual switch.

11. Control mechanism for a multiple drive ratio power transmission of a motor vehicle having an engine including ignition means, relatively fast speed driving means including positively interengageable drive control elements adapted to establish a, drive therethrough when engaged, said elements being subject to torque loads when engaged and being freely disengageable only when said loads are relieved, and relatively slow speed driving means including a device automatically operable to establish a drive therethrough in response to release of the fast speed driving means; said control mechanism comprising electromagnetic means adapted when energized to urge one of said elements in one direction of its movement, yielding means to urge said one element in the other direction of its movement, means for establishing an energizing circuit through said electromagnetic means, means for establishing two circuits in parallel through said ignition means for energizing the same, said last means including a switch controlled in accordance with the position of said drive control elements, adapted to effect the opening of one of said ignition circuits when said drive control elements are engaged, and including a first manual switch for effecting the opening of the other of said ignition circuits while said previously mentioned switch is open, thereby to interrupt the ignition and relieve the torque load on-said drive control elements, said means for establishing an energizing circuit including a second manual switch arranged to be opened in unison with said first manual switch.

12. Control mechanism as defined in claim 11, wherein said manually operated switches ar both throttle-operated.

PALMER ORR. 

